SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0a4d3f19d26c1d64cde273c315b1e0b3866311369cd18772f233864bf989f0c' 
  AND token = 'jA66bUXzFNEPPJA74qhGFqGfY1QBkBGpNAi7/mZnGrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}